液体介质传热渐进温成形研究

Research on incremental warm forming by liquid medium heat-transfer

由于液体介质的存在,在以导热油直接作为传热介质加热板料实现板料温热渐进成形中,成形初始的预胀以及成形过程中存在的背压是区别于其他渐进成形方法的显著特征。在数控渐进机床上,首先以2A12铝合金板料对成形过程中液体压力产生的板料预胀和过程背压的影响进行了研究,然后采用SUS304不锈钢板料对成形过程中的导热油温度影响进行了研究。研究结果表明:液体介质较小的压力产生的预胀和背压对成形过程没有显著影响,成形过程中为了保证导热油和板料充分接触,导热油可以保持一定的系统压力;采用液体介质直接作为传热介质加热板料进行板料温渐进成形是可行的;温度对SUS304不锈钢板渐进成形性能影响显著。

For the existence of liquid medium, during the sheet incremental warm forming realized by heat conduction oil as heat-transfer medium, the distinguishing features that distinguished from other incremental forming methods are pre-bulge during the initial forming and backpressure during forming process. The influence of pre-bulge and backpressure induced by liquid medium was investigated during the forming process of alloy sheet 2A12. Moreover, the influence of liquid medium temperature on forming process was studied using SUS304 sheet. The results show that there is little influence of pre-bulge and backpressure induced by low liquid pressure on forming process, the system pressure should be kept in order to make the liquid medium and the sheet contact enough. It is feasible that the incremental warm forming of metal sheet heated by oil medium directly. In addition, the temperature has prominent influence on the formability of SUS304.